Development of a spatially dispersed short-coherence interferometry sensor using diffraction grating orders

Mothana A. Hassan, Haydn Martin, Xiangqian Jiang

Research output: Contribution to journalArticle

1 Citation (Scopus)


Modern manufacturing processes can achieve good throughput by requiring that manufactured products be screened by better quality control exercised at a quicker rate. This trend in the quality control of manufactured products increases the need for process-oriented precision metrology capable of performing faster inspections and yielding valuable feedback to the manufacturing system. This paper presents a spatially dispersed short-coherence interferometry sensor using diffraction orders of the zeroth and first order for a diffraction grating introduced as a new compact system configuration for surface profile measurement. In this modified design, the diffraction grating acts as the beam splitter/combiner. Diffractions for the zeroth and first orders are represented by the reference and measurement arms, respectively, of a Michelson interferometer, which reduces the optical path length. This innovative design has been proven effective for determining the step-height repeatability in the sensor range from 27 nm to 22 nm for profiles spanning the step heights of the tested specimens.
Original languageEnglish
Pages (from-to)6391-6397
Number of pages7
JournalApplied Optics
Issue number22
Publication statusPublished - 1 Aug 2017


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